MUMBAI: Construction of the proposed Gargai dam, a key water supply project aimed at augmenting Mumbai’s future water needs, is expected to begin in October 2026, with the reservoir likely to be filled by May 2029. The announcement was made by Abhijit Bangar, additional municipal commissioner (projects) at the standing committee on Wednesday.Gargai dam work to begin in October 2026, completion targeted by 2029: BMCThe project includes a 69-metre-high dam near Ogada village and a 2.2-km tunnel that will channel water to the Modak Sagar reservoir. The Brihanmumbai Municipal Corporation (BMC) has targeted completion of the project by May 2029 and had proposed a budgetary provision of ₹437.51 crore for the Gargai project in its 2026–27 Budget Estimates.Bangar said the dam will use roller compacted concrete (RCC) technology, a method that allows faster construction as the concrete does not require conventional curing. “The dam has RCC-type concrete and we need to place around 450mm concrete layers,” he said.However, the project remains dependent on securing critical environmental clearances. “The most important approval is the forest diversion permission,” Bangar said, adding that two permissions from the Ministry of Environment, Forest and Climate Change (MoEFCC), along with approval from the National Board for Wildlife, are still pending.According to officials, the delay in obtaining MoEFCC clearance stemmed from the lack of sufficient land for compensatory afforestation, a shortfall that has now been addressed.The project has significant environmental and social implications, with two villages directly affected by submergence and four additional villages earmarked for relocation and rehabilitation.An official said around 310,000 trees will be transplanted as part of the project mitigation measures. “Compensatory afforestation is planned across 658 hectares in Washim, Chandrapur and Hingoli, while all residents from affected villages will be shifted to Devali in Wada taluka with full infrastructure,” the official said.The 658 hectares identified for compensatory afforestation will offset forest land diverted for the project. In addition, around 350 hectares of land spread across four of the six affected villages will be incorporated into forest land after transplantation measures are completed. Two villages are expected to be submerged due to the reservoir.On rehabilitation, officials said nearly 400 hectares of land belonging to the Forest Development Corporation of Maharashtra in Devali, Wada taluka, has been identified for resettlement and rehabilitation of affected residents.Meanwhile, preliminary technical work has already begun. Geotechnical soil investigations are underway at the site to assess ground conditions and finalise engineering specifications ahead of construction.